It is known in the art to utilize positive displacement compressors, such as roots-type and screw-type compressors, having lobed rotors for supercharging internal combustion engines and for providing compressed air for other purposes. Such a compressor, when used as an automotive supercharger, may include a housing having a rotor cavity in which a pair of rotors, having interleaved lobes, rotates to transport volumes of intake air between an inlet passage of the housing and an outlet passage of the housing thereby increasing the pressure at the outlet passage.
Sustained high load operation of the supercharger increases the air temperature exiting the supercharger, with the highest temperatures typically reached at high engine speeds and supercharger loads. The air tends to heat lubricating oil within a gear drive assembly of the supercharger by forced convection/conduction.